A soldering iron is required for soldering and disassembling components.
1. Get rid of the oxide layer. The purpose of removing the oxide layer is to make it easy for the soldering iron tip to be dipped in solder during welding. Before using the soldering iron, you can use a knife or file to gently remove the oxide layer on the soldering iron tip. After the oxide layer is scraped off, the metal will be exposed. luster.
2. Dip in flux. As shown in picture b, after the oxide layer of the soldering iron tip is removed, energize the soldering iron to heat the tip, and then dip the tip in rosin. You will see rosin vapor emitting from the tip. The function of rosin is to prevent the soldering iron tip from oxidizing at high temperatures and enhance the fluidity of the solder, making welding easier.
3. Hang tin. When the soldering iron tip is dipped in rosin and reaches a sufficient temperature, rosin vapor will emerge from the soldering iron tip. Apply solder to the head of the soldering iron tip and apply a layer of solder to the head of the soldering iron tip.
The advantage of hanging tin on the soldering iron tip is to protect the soldering iron tip from oxidation and make it easier to weld components. Once the soldering iron tip is "burned", that is, the temperature of the soldering iron tip is too high, the solder on the soldering iron tip evaporates, and the soldering iron tip is Burnt black and oxidized, it will be difficult to solder components. At this time, the oxide layer needs to be scraped off and then tinned before use. Therefore, when the soldering iron is not used for a long time, the power supply should be unplugged to prevent the soldering iron from "burning out".
4. Welding of components
When welding components, first gently scrape off the oxide layer on the pins of the components to be welded, then energize the soldering iron, dip it in rosin after heating, and when the temperature of the soldering iron tip is sufficient, turn the soldering iron tip at a 45° angle. Press it on the copper foil next to the pins of the component to be soldered on the printed circuit board, and then touch the soldering iron tip. The solder wire melts and becomes liquid, which will flow around the component pins. At this time, move the soldering iron tip. When the solder is turned on, the component pins and the copper foil of the printed circuit board are welded together.
When welding components, the soldering iron tip should not be in contact with the printed circuit board and components for too long to avoid damage to the printed circuit board and components. The welding process should be completed within 1.5 to 4 seconds. During welding, the solder joints must be smooth and the solder is evenly distributed.
5. Disassembly of components
When disassembling the components on the printed circuit board, use the soldering iron tip to touch the solder joints at the component pins. After the solder at the solder joints melts, pull out the component pins on the other side of the circuit board. , and then use the same method to solder the other pin. This method is very convenient for disassembling components with less than 3 pins, but it is more difficult to disassemble components with more than 4 pins (such as integrated circuits).
